665340127 has 4 divisors (see below), whose sum is σ = 688282920. Its totient is φ = 642397336.

The previous prime is 665340107. The next prime is 665340163. The reversal of 665340127 is 721043566.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 721043566 = 2 ⋅360521783.

It is a cyclic number.

It is not a de Polignac number, because 665340127 - 2¹⁹ = 664815839 is a prime.

It is a super-2 number, since 2×665340127² = 885354969192752258, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 665340092 and 665340101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665340107) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11471353 + ... + 11471410.

It is an arithmetic number, because the mean of its divisors is an integer number (172070730).

Almost surely, 2^665340127 is an apocalyptic number.

665340127 is a deficient number, since it is larger than the sum of its proper divisors (22942793).

665340127 is a wasteful number, since it uses less digits than its factorization.

665340127 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22942792.

The product of its (nonzero) digits is 30240, while the sum is 34.

The square root of 665340127 is about 25794.1878530804. The cubic root of 665340127 is about 873.0006604301. Note that the first 3 decimals are identical.

The spelling of 665340127 in words is "six hundred sixty-five million, three hundred forty thousand, one hundred twenty-seven".